(Contest is now judged. Results are here.)
First, here’s Nobel Prize winner Steven Weinberg:
… There is also a less creditable reason for hostility to the idea of a multiverse, based on the fact that we will never be able to observe any subuniverses except our own. Livio and Rees, and Tegmark have given thorough discussions of various other ingredients of accepted theories that we will never be able to observe, without our being led to reject these theories. The test of a physical theory is not that everything in it should be observable and every prediction it makes should be testable, but rather that enough is observable and enough predictions are testable to give us confidence that the theory is right.
– Steven Weinberg, “Living in the Multiverse,” The Nature of Nature, p. 554
So, for a free copy of The Nature of Nature what would be acceptable evidence that other such universes exist? Contest Judged Saturday, April 23.
Enter by posting a comment to this post.
You may get some ideas here.
(Note: A “hi” from any of the parties pictured below will not be considered evidence in this contest.)